Cities are breeding grounds for possibilities...
Almost anything and everyone has a chance to be good, bad, heroic, evil, mundane, and magical. And most things, and people, are hybrids.
Consider the countless opportunities for people to develop unique, innovative solutions to their problems; consider the challenge of surviving in the chaos of a teeming city where survival is a challenge; consider the opportunities for complete failure; and consider the options available.
The urban environment is not forgiving and you should count on survivors using whatever tools they have at hand.
You even need to expect magic. Always expect magic, even if there might be a cruder, more expedient, more obvious way of doing things, because witches are people.